Cracking

Cause

Excessive film thickness of the undercoat and/or topcoat.
Refinishing over a previously crazed/cracked surface.
Insufficient flash time between coats and/or force drying undercoats using air from the spray gun.

Mixing incorrectly or using too much hardener.
Paint ingredients not thoroughly stirred or agitated.
Breakdown of finish due to prolonged exposure to sunlight, moisture, and extreme temperature changes.
Using generic reducers and/or hardeners.

Repair

Remove all cracked paint film and refinish.

Prevention

Apply all materials following label direction.
Completely remove crazed/cracked finishes before refinishing.
Do not force dry undercoats by fanning with spray gun air.
Mix ingredients thoroughly using the recommended additives. Add each component in proper sequence following the recommended mixing ratio.
Stir or agitate materials thoroughly before use to ensure all ingredients are in solution.
Use premium two component undercoat and topcoat system to provide maximum gloss and durability.
Use the recommended thinner/reducer and hardener, and then measure accurately.

Dust Contamination

Cause

Inadequate cleaning of the surface to be painted.
Dirty spraying environment.
Inadequate air filtration or unfiltered air entering the booth.
Dirty or unsuitable work clothes that contain dust, lint, or fibers.
Particles from deteriorated air supply lines.
Using a poor grade masking paper.
Dirty spray gun.
Removing the vehicle from the spray booth before the finish is"dust free".

Repair

Sand with 1200 or finer grid sandpaper, then compound and polish to restore gloss.
Or, sand smooth and refinish.

Prevention

Thoroughly blow off around windows, doors, jambs, hood, trunk, moldings, engine compartment, and wheel openings. Wipe the surface to be painted and the masking paper with the tack rag.
Maintain a clean working area.
Install proper air filters. Never use residential-type furnace filters in the spray booth. Repair any leakage found in the spray booth due to poor fitting doors, gaskets, seams or filters.
Wear a lint free paint suit during the spray application.
Use quality masking materials. "Wicks" found on newspaper can break away and blow into the wet paint.
Repair or replace defective air lines.
Properly clean and maintain spray equipment.
Vehicle should be kept in a clean environment until finish is "dust free"

Prevention

Check questionable finishes by rubbing a small inconspicuous area with a shop towel saturated with lacquer thinner. Finishes susceptible to lifting will soften, wrinkle or shrivel as lacquer thinner is applied. If any of these reactions occur, the following recommendations should be considered.

Fisheyes

Cause

Spraying over surfaces contaminated with oil, wax, silicone, grease, etc.
Use of thinner/reducer in place of a solvent cleaner.
Spraying over previously repaired areas containing "fisheye eliminator" additive.

Repair

Remove wet paint film with solvent, clean and refinish.
Add the recommended fisheye eliminator and respray the affected area.
If fisheyes appear in a basecoat, allow the color to flash then spray a mist coat over affected area. Do not use fisheye eliminator in undercoats or basecoat color.
If the paint has dried, sand to a smooth finish below the fisheye cratering and refinish.

Prevention

Thoroughly clean the surface to be painted with detergent and hot water, followed by the recommended solvent cleaner. Wipe dry with clean rags.
Use fisheye eliminator that is specifically recommended for the topcoat.
Install an air filtering system that removes and prevents oil and moisture contamination.
Maintain air supply by draining, cleaning and changing filter(s) on a routine basis.

Lifting

Cause

Solvents in a newly applied product attack the previous finish causing wrinkling, raising, or puckering of the paint film due to:
Recoating enamels or urethanes that are not fully cured.
Exceeding maximum flash or recoat times during application.
Recoating a basecoat/clearcoat finish, where existing clearcoat has insufficient film build.

Repair

Remove lifted areas and refinish.

Prevention

Check questionable finishes by rubbing a small inconspicuous area with a shop towel saturated with lacquer thinner. Finishes susceptible to lifting will soften, swell or shrivel as lacquer thinner is applied. If any of these reactions occur, the following recommendations should be considered.

Do not exceed a product's maximum recoat time during or after application.
Allow enamels or urethanes to thoroughly cure before recoating or attempting a repair.
Avoid applying undercoats or topcoats excessively wet.
Avoid the use of lacquer products over an air dried enamel finish.
When insoluble material (enamel/urethane) has been applied over a soluble material (lacquer):
avoid sanding through and exposing areas of the soluble material.
apply two component primer surfacer and/or sealer as a barrier between the new and the old finish. When applying two component undercoats over soluble finishes, the complete panel must be coated.
Use water borne undercoats to repair extremely sensitive finishes.

Loss of Gloss

Cause

Topcoat applied in heavy, wet coats.
Inadequate flash time between coats.
Insufficient film thickness of topcoat color or clearcoat.
Insufficient drying/curling of undercoats before applying topcoats.
Using a poor grade and/or too fast evaporating thinner/reducer for spray conditions.
Improper cleaning of the substrate.
Insufficient air movement during and after application.
Spraying over a deteriorated or solvent sensitive substrate finish without proper priming or sealing procedures.
Natural weathering of the finish.

Repair

Prevention

Apply the topcoat according to product label directions using the recommended gun set-up and air pressure.
Allow all coatings sufficient flash between coats.
Apply sufficient number of coats to achieve recommended proper film thickness. Check with film thickness gauge if possible.
Allow undercoats to thoroughly dry/cure before topcoating.
Select recommended thinner/reducer based on temperature, humidity, air movement, and size of repair.
Clean substrate thoroughly before and after sanding.
For air dry situations:
allow exhaust fan to run 40 minutes or longer after spraying;
open booth doors after finish is dust free; and
maintain a shop temperature of 60 degrees fahrenheit or above, especially when drying overnight.
For maximum holdout, use a premium two component undercoat system.
Properly wash and care for the finish on a regular basis.
Using premium topcoat color or clearcoat system will provide maximum gloss and durability.

Repair

Prevention

Use proper reduction ratio and spray at recommended air pressure.
Select recommended thinner/reducer based on temperature, humidity, air movement, and size of repair.
Avoid heavy coats and excessive film thickness.
Use recommended spray gun, fluid tip and air cap for the material being sprayed. Always adjust the gun for best atomization and balanced spray pattern before paint application.
During paint application, hold the gun perpendicular and parallel to the surface. Adjust speed of pass, pattern overlap, and distance from the panel to achieve the desired appearance.

Peeling

Cause

Improper preparation of the substrate (sanding and cleaning).
Omitting or applying an incompatible undercoat to a specific substrate (e.g. aluminum, galvanized, plastics, etc.).
Insufficient flash/dry time or exceeding the product's maximum recoat time.
Insufficient film thickness of undercoat, or topcoat.

Clearcoat finishes:

Insufficient film thickness of clearcoat.

Solvent cleaning basecoat before clearcoating.

Sanding basecoat before applying additional basecoat or clearcoat.

Basecoat applied too dry.

Clearcoat applied too dry.

Baking basecoat before applying clearcoat.

Using fisheye eliminator in basecoat.

Incompatible clearcoat.

Use of incompatible "adhesion promoter".

Excessive basecoat film thickness.

Over reduction, under reduction, or incompatible reducer used in basecoat.

Repair

Remove the finish in the affected area, featheredge, and refinish.
Or, strip to bare substrate and refinish.

Prevention

Clean and prepare all substrates according to product recommendations.
Use the recommended undercoat (primer) for the substrate being finished. Plastic parts may require use of special primer and flex additive for maximum performance.
Recoat all products within their recommended minimum and maximum recoat time.
Apply a sufficient number of coats to obtain the recommended film thickness.
Follow basecoat/clearcoat application procedures using only recommended/compatible products.
"Adhesion promoter" should only be used when specifically recommended.

Repair

Remove the wet paint film with solvent, clean and refinish.
Or, after finish is completely dry. remove excess paint by block sanding with 1200 or finer grit sandpaper, compound and polish to restore gloss.
Or, block sand smooth and refinish.

Prevention

Mix according to product directions. Select recommended solvent for spray conditions based on temperature, humidity, air movement, size of repair.
Spray medium wet coats and allow sufficient flash time between coats.
Adjust the spray gun for the best atomization and balanced spray pattern before paint application. Hold the spray gun perpendicular and parallel to the panel. Adjust speed of pass, pattern overlap, and distance from the panel until the desired results are achieved.
Set air pressure at the gun according to product recommendations.
Use recommended spray gun, including fluid tip and air cap combination.
Allow the paint material and substrate to reach room temperature before application

Repair

Allow finish to dry, sand and refinish

Prevention

Avoid sanding basecoat finishes before clearcoating. If sanding is necessary apply additional color following label direction.
When sanding single stage finishes confine the sanding to minor imperfections (nib sanding rather than entire panels). For best results use 1200 or finer grid sandpaper.

Solvent Popping

Cause

Liquid solvent (thinners/reducers) becomes "trapped" in the paint film when the surface layer skins over too quickly, preventing their evaporation into the atmosphere. Solvents that vaporize within the paint film leave bubbles, pinholes or craters as they push through and "pop" the surface. Solvents can be trapped due to:

Thinner/reducer evaporating too fast for spraying conditions
Inadequate flash time between coats
Excessive film thickness or "piling on" of heavy/wet coats
Too much air movement causing surface to "skin over" before solvents evaporate
Excessive purge/flash time before force drying.

Repair

Allow finish to thoroughly dry/cure, sand smooth and refinish. Inspect surface carefully to ensure all craters have been removed.
Severe popping will require removal of the affected film. Prime, seal and recoat, as necessary.

Prevention

Select recommended thinner/reducer based on temperature, humidity, air movement and size of repair
Allow for proper flash time between coats.
Avoid "piling on" or double wet coats.
Restrict air movement over the surface being painted.
Avoid extended purge/flash time before force drying.

*Two component acrylic urethane primer surfacer and acrylic urethane sealer may be used to top a majority of body filler staining problems. Both are required and must be allowed to fully cure for maximum stain resistance. However, for 100% assurance against body filler staining, use a non-staining body filler according to manufacturer's recommendations.